Basement Contractor has placed a lien on our home

In Ontario, more specifically Toronto.

I would love advice on how best to resolve this situation:

- I have a signed contract for underpinning and a new addition

- the contractor has up to date builders insurance and WSIB

- He was aggressive from the 1st day, demanding an extra $5k for removing the old foundations from an addition that I had the contract revised to include prior to starting.

He had skipped a meeting the week prior to review the work and site before starting (in hopes to avoid situations like this)

- I did not budge and he grudgingly gave in and started the work, the underpinning was done well and fast but then they quickly poured the foundation for the new addition and put the block walls up in a day

- when I inspected the site (they were not there) I informed him by email that I wanted the weeping tile included on the outside as per the drawings and I wanted the joint between old and new to be properly sealed and parged, they had left big voids and cracks in this joint.

- instead they just covered the wall with parging, tar and a delta membrane and backfilled. He claimed to have not seen the email

- he refused to correct this work arguing that I had sandy soil (pure sand), I was on a hill and I had a new membrane and weeping tile throughout the basement on the inside

- he is now demanding payment in full, claiming he is done.

- the basement floor has not been poured, he offered $4500 off for this but the floor is 800 sq. ft. and I don't think I can get anyone in this City to do this work for much less than $6000 at a minimum. I find the going rate is $8-10 per sq. ft. for new concrete

- he has threatened to lien a few weeks ago and suggested I read my contract.

I responded that I had and that his own terms and conditions stipulate that any disputes over payment or work go to mediation as agreed by both parties. Any changes to the contract must be authorized in writing by a company official and that the drawings for the project define the work and how it is to be done. In my case, he has not followed the permit drawings in respect to the weepier.

I did offer to pay the difference between the balance owing less the 10% holdback (as per his terms and conditions) and the value of the floor.

I believe there is close to $21,000 owing in total and he just emailed a lien claim for $26,500.

This claim is just an email but perhaps he will send me a formal claim this week.

Any suggestions on how best to resolve this would be much appreciated.

I do project management for construction all the time and we have never had to threaten a lien. We do get silly complaints and unfair requests quite often but we just deal with it and try to make the client happy. Over the years I have paid tens of thousands to fix our own mistakes. It is the cost of doing business and they were our mistakes.

In this case I really do feel like many shortcuts were taken and that this company is used to bullying the client/homeowner to accept poor work, unfinished work and damage to property.

Any suggestions on how best to resolve this would be much appreciated.